I went aboard the NS Savannah when she was on display in Charleston SC harbor. And the criticism that she was neither fish nor fowl is correct. Too much space was taken up by visitor/passenger compartments that could have been used for cargo. Or vice-versa.

The article also mentioned that she was built just as the container revolution was beginning, and that also doomed her to a diminishing availability of bulk cargo to haul.

Overall impressions were that it was a really nice ship. Too nice. It had portholes with rotating shades made of polarizing filters - you spun the inner one 180 degrees to block out the sun. Which is very very cool, but not something a cargo ship would normally feature.

Would a modern mega-huge container ship benefit from being nuclear powered? Maybe. The additional shielding and steel bracing needed to protect the piping and core would add significant cost to the construction, but the zero extended fuel cost might make that cost efficient. A larger question is whether a nuclear powered ship would be allowed in some ports, such as Japan or New Zealand.